A vent (also referenced to herein as a “venting channel”) is an important part of a hearing aid. A vent is required to provide air circulation and minimize occlusion. If a vent is not provided, a user will likely have an uneasy feeling caused by an unequal pressure differential present in a space between the users ear drum and an inner ear canal end of the hearing aid housing compared to the atmospheric pressure external to the hearing aid housing outwardly of the ear. Users have described this uneasy feeling as an unnatural pressure differential. Users have also complained of what has been described as an unnatural hollow sound when the hearing aid is used if no vent is provided. Furthermore, care must be given in choosing the size of the vent since if the vent is too large, undesirable acoustic feedback may occur. When marketing experts in the hearing aid industry are asked which shell they would consider ideal, many of them will indicate a shell as small as possible, but with a vent as big as possible. The term “shell” used herein means an outermost wall of the hearing aid housing.
A “collection vent” is a known prior art vent in hearing aids which starts as a regular round vent at a faceplate outer side of the hearing aid (also called a “starter vent” hereafter) and continues some distance as a round vent and then increases in diameter gradually until some size specified by a designer and which terminates at the canal side of the hearing aid near the ear drum.